Flexible hose incorporating extensible conductive tape

ABSTRACT

A flexible hose having a conductor element extending along the hose wall. The conductor element is in the form of an elastic conductive strip or tape having a generally flat configuration and formed of elastic yarns or threads extending along the strip or tape and flexible metal wires or threads of metal braided, plaited or interwoven with the elastic yarns or threads. The conductive element being of this form is of use especially for extruded hoses, since it can be laid along the hose parallel to the hose axis and will stretch to accommodate hose elongation.

United States Patent [72] Inventor Aristovoulos George PetzetakisThessalonikis & Chandri St., Moschaton, Piraeus, Greece [21] Appl. No.735,639 [22] Filed Jun: 10, 1968 {45] Patented Jan. 12, 1971 [32]Priority June 24, 1967 [33] Greece [31] No. 35,261

[54] FLEXIBLE HOSE INCORPORATING EXTENSIBLE CONDUCTIVE TAPE 5 Claims, 6Drawing Figs.

[52] US. Cl 174/47, 174/69,174/1l7;317/2 [51] Int. Cl H051 3/00, F16]11/12 [50] Field of Search 174/47, 69, 117.2; 317/2; 340/320; 138/103[56] References Cited UNITED STATES PATENTS 646,886 4/1900 Stowe et a1.

Primary Examiner Laramie E. Askin At!0rneyCushman, Darby & CushmanABSTRACT: A flexible hose having a conductor element extending along thehose wall. The conductor element is in the form of an elastic conductivestrip or tape having a generally flat configuration and formed ofelastic yarns or threads extending along the strip or tape and flexiblemetal wires or threads of metal braided, plaited or interwoven with theelastic yarns or threads. The conductive element being of this form isof use especially for extruded hoses, since it can be laid along thehose parallel to the hose axis and will stretch to accommodate hoseelongation.

PATENYEB 4m 1 2 1971 ELASTIC YARN-77 COPPER THREADS-72 HG, 4.

Aiw/ 9 MAW ATTORNEY FLEXIBLE HOSE INCORPORATING EXTENSIBLE CONDUCTIVETAPE The present invention relates to hoses, and more particularly tohoses incorporating conductors to avoid or lessen the risk of excessivestatic electrical charges in the hoses.

It is known that there is a tendency for the conveyance of certainsubstances, surh as inflammable fuels, grain or pulverized material,through flexible hoses of electrically insulating material to inducestatic electrical charges in the hoses.

It is also known for flexible hoses of rubber material which are toconvey such materials each. to incorporate a metallic conductor wireextending helically along the wall of the hose, the conductor wire lyingeither on the inner or outer surface of the hose wall or in the hosewall. The conductor wire is able to conform to bending and/or elongationof the hose by reason of the helical configuration of the conductorwire.

Such a hose is usually made by superimposing layers of rubber, textilematerial and the helical wire. It is relatively difficult and/orexpensive to incorporate a helical conductor wire in a hose produced byextrusion.

It is an object of the invention to provide an alternative form ofconductive element for incorporation in a flexible hose.

It is envisaged that an important application of the invention will beto hoses of which the hose walls are produced by extrusion, but theinvention may have other applications.

According to the invention there is provided a flexible hose having aconductor element extending along the hose wall, the conductor elementbeing in the form of an elastic conductive strip or tape, the strip ortape being generally of flat configuration and formed of elastic yarnsor threads extending along the strip or tape and flexible metal wires orthreads of metal braided, plaited or interwoven with the elastic yarnsor threads.

The invention will be described by way of examples with reference to theaccompanying drawings, wherein:

FIGS. 1A and 1B are a side view and anend view respectively of aconductor element in the form of an elastic conductive tape, to extendalong a hose wall in accordance with the invention;

FIG. 2 is a side elevation of a small length of hose incorporating thetape of FIG. 1 in accordance with the invention;

FIG. 3 is a cross section through another hose in accordance with theinvention;

FIG. 4 is a cross section through another hose in accordance with theinvention;

FIG. 5 is a cross section through another hose in accordance with theinvention; and

FIG. 6 is a cross section through a fifth hose in accordance with theinvention.

Referring to FIGS. 1A and 1B, there is shown an elastic tape 10consisting of parallel extremely fine elastic yarns 11, preferably butnot necessarily of thermoplastic polyurethane,

on which very fine metallic wires 12, of copper, have been.

braided at such an angle, determined empirically, as to permit elasticelongation of the tape 10 and eventual restoration of the tape 10 to itsoriginal length.

The tape 10 may be made by means of an ordinary braiding machine'as iscommonly used for making elastic fabric belts, with the exception thatcopper 'wires are used instead of fibre yarns, so that the tape 10 shallbe electrically conductive.

The hose shown in FIG. 2 comprises a hose wall 21 preferably, but notnecessarily, made by extrusion, and the tape 10 extending along the hosewall 21 parallel to the axis of the hose 20, in the external surface 22of the hose wall 21. The materials of the hose wall 21 and the elasticyarns 11 are, for this purpose, preferably compatible with each other.

The tape 10 and its incorporation thus in the hose 20 provides threecharacteristics. Firstly, the tape 10, being elastic, is able to conformto any bending and elongation of the hose 20. Secondly, being generallyflat, it does not damage the hose wall 21 or reduce the strainresistance of the hose wall 21. Thirdly, it takes up little space.

The tape 10 can be incorporated in the hose 20 during extrusion of thehose wall 21, without much difiicult Fig. 3 shows a modified hose 23similar to the liose 20 that the tape 10 is coated with a protectivecovering 24 of a plastics material which is compatible with the hosewall 25 and which is fused to the hose wall 25.

The hose 23 may be made in a similar manner to the hose 20.Alternatively, by reason of the provision of the plastics covering 24the tape 10 and the covering 24 may both be applied to the hose wall 25after the hose wall 25 has already been formed.

As will be seen from FIG. 3, the covering 24 completely envelopes thetape 10, and it is envisaged that the covering 24 will be already on thetape 10 when the tape is applied to the hose wall 25.

FIG. 4 shows a modified hose 26 with tape 10 incorporated in theexternal surface 27 of the hose wall 28 and with a cover ing 29, ofplastics material compatible with the material of the hose wall 28,fused to the hose wall 28. In this case, the covering 29 is over onlythe outside of tape 10.

FIG. 5 shows a modified hose 30 in which tape 10 is embedded within thehose wall 31. In this case in particular, it is highly desirable thatthe elastic yarns 11 (FIGS. 1A and 1B) and the hose wall 31 should be ofmutually compatible materials.

FIG. 6 shows a further modified hose 32 in which the tape 10 isincorporated in the inner surface 33 of the hose wall 34. In this casealso, the yarns 11 (FIGS. 1A and 1B) and the hose wall 34 should be ofmutually compatible materials.

Tape 10 may have a wider or looser braiding, that is to say, so thatthere are distinct gaps between the braided wires.

By incorporating the tape 10 in the hoses 20, 26, 30 and 32 duringproduction of the hose walls 21, 28, 31 and 34 by extrusion, while thehose walls are stillnot set, the materials of the hose may be made tofill up the interstices of the tape 10, particularly if the yarns 11 areof compatible materials.

In use, the tape 10 is earthed so as to conduct electrostatic chargesaway to prevent or reduce the risk of fire or explosion, and generallyto increase the safety of the environment in which the hose is used.

I claim:

1. A flexible hose of a thermoplastic material, the wall of said hoseincluding an extensible conductive tape having a generally flatconfiguration and extending parallel to the hose axis, said extensibleconductive tape comprising extremely fine elastic yarns of a materialcompatible with the thermoplastic hose wall material extendinglongitudinally of said tape and braided with very fine metal threads todefine a plurality of interstices, and the thermoplastic material ofsaid hose wall filling the interstices of said extensive conductivetape.

2. A hose according to claim 1, wherein said tape is located adjacentthe inner surface of said hose wall.

3. A hose according to claim 1, wherein said tape is located adjacentthe outer surface of said hose wall.

4. A hose according to claim 1, wherein the material of said yarns isthermoplastic polyurethane.

5. A hose according to claim 1, wherein the metal of said threads iscopper.

1. A flexible hose of a thermoplastic material, the wall of said hoseincluding an extensible conductive tape having a generally flatconfiguration and extending parallel to the hose axis, said extensibleconductive tape comprising extremely fine elastic yarns of a materialcompatible with the thermoplastic hose wall material extendinglongitudinally of said tape and braided with very fine metal threads todeFine a plurality of interstices, and the thermoplastic material ofsaid hose wall filling the interstices of said extensive conductivetape.
 2. A hose according to claim 1, wherein said tape is locatedadjacent the inner surface of said hose wall.
 3. A hose according toclaim 1, wherein said tape is located adjacent the outer surface of saidhose wall.
 4. A hose according to claim 1, wherein the material of saidyarns is thermoplastic polyurethane.
 5. A hose according to claim 1,wherein the metal of said threads is copper.